There is always the issue of the mob dying or getting killed before the full completion of a DoT. This is especially bad for Bane of Agony, that causes more of its damage in the last third of its duration.

There are also some issues with using DoTs in parties and raids. In particular, many Crowd Control abilities break if the affected creature takes any damage. A mob affected by a DoT spell essentially becomes immune to a significant number of CC measures.

This build places more emphasis on your own DPS. You can actually pick Glyph of Bane of Agony instead of Glyph of Unstable Affliction if you like to cast Bane of Agony instead of Bane of Doom. Always use either Bane of Doom/Curse of Agony combined with Curse of the Elements. Bane of Doom now have the advantage to have a 20% chance of summoning a demon guardian.

Glyph of Fear is now very usefull now when fear can be used as a cc, it's probably a good idea to stick with that, though Glyph of Soul Link can be changed to fit you better.

The basic opening rotation:

With no Unholy Death Knight, Boomkin, or warlock that's willing to cast Curse of the Elements:

Fire Raiding Destro (0/5/31)

This build is pure DPS. No raid support or survival talents. Minion of choice is the Imp due to Empowered Imp and is supported by Burning Embers and Dark Arts. You will have the imp on Defensive and will disable auto cast of Phase Shift so he will be buffed as well.

Opening rotation with the expectation of Improved Shadowbolt being provided by someone else, as well as Curse of the Elements/Earth and Moon/Ebon Plague:

Talents: Demonic Embrace can be changed to Fel Synergy (as utility) or to Doom and Gloom (as a further improvement to the damage capabilities of this build) if you like it more; otherwise I suggest to stay with the glyph and talents, glyph of fear is excellent now when fear can be used as a cc on certain mobs.

Soul Leech Chaos Bolt, Shadowburn and Soul Fire are all three major spells, thus used often. 4% Health and mana every time these spells are casted increases survibality and durability.

Nether Ward gives a powerful shield against any type of spell. (Watch out for spellsteal)

Nether Protection gives a significant damage reduction for the same spell school. This comes in handy against classes that rely heavily on a single spell school (nearly all classes) and increases survivability.